# CII-SR-466

Source: https://xmlvalid.com/rules/CII-SR-466

> Only one BT-56 element is allowed on an invoice.

- Level: warning
- Rule sets: EN 16931 rules (CII) 1.3.17, EN 16931 rules 1.3.16 (CII), EXTENDED-CTC-FR rules (CII) 1.4.0.04
- Context: `/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement`
- Test: `not(ram:BuyerTradeParty/ram:DefinedTradeContact/ram:PersonName and ram:BuyerTradeParty/ram:DefinedTradeContact/ram:DepartmentName)`

> Only one BT-56 element is allowed on an invoice.

- Level: error
- Rule sets: Factur-X BASIC WL rules 1.09, Factur-X EN 16931 rules 1.09.2, Factur-X EXTENDED rules 1.09.2
- Context: `/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement`
- Test: `not(ram:BuyerTradeParty/ram:DefinedTradeContact/ram:PersonName and ram:BuyerTradeParty/ram:DefinedTradeContact/ram:DepartmentName)`

Validate a document against these rules: https://xmlvalid.com/validate